As an established Center with a strong enrollment history, The University of Colorado Denver (UCD) Center is uniquely positioned to continue as an active and valuable participant in the NICHD MFMU Network. The strengths of this proposal include: 1) a solid enrollment track record during our first cycle (rank 6-9 out of 14 centers in current studies), 2) an established team of professional research assistants and research nurses that are now well-versed in MFMU processes and protocols, 3) exceptionally strong departmental and institutional commitments to participate in MFMU research bolstered by excellent departmental grants and contracts, IRB, budget and administrative support, 4) a mature MFM faculty deployed at both the University of Colorado Denver and the Denver Health sites with leadership in conducting large multicenter trials and a comprehensive range of specific clinical strengths, 5) a thirty-year history of collaboration on research projects and clinical care between the obstetricians and neonatologists at the both the University of Colorado and Denver Health sites, and 6) the Department's Basic Research Science division and the Colorado Clinical and Translational Sciences Institute that together have extensive experience with translational research and access to numerous research cores on campus. With combined annual deliveries nearing 7000 from an ethnically and economically diverse population in the intermountain west, our geographic and population attributes are additional and important assets that the Colorado Center brings to the MFMU Network.